Glaciers are massive, slow-moving rivers of compacted ice that carve striking topographical features across Earth’s high-latitude and high-altitude regions. Divided broadly into alpine glaciers and continental ice sheets, these dynamic agents reshape landscapes through powerful erosional mechanisms like plucking and abrasion. As ice advances and retreats, it leaves behind distinctive erosional forms such as U-shaped valleys, cirques, and hanging valleys along with depositional landforms like moraines, drumlins, and eskers. Mastering glacial geomorphology is essential for understanding Earth’s climatic history, past ice ages, and surface landscape evolution.
1. Which of the following best defines a glacier?
Correct Answer: b) A large mass of perennial ice resting on land or floating shelf-like in the sea adjacent to land, formed from the accumulation and recrystallization of snow
Explanation:
A glacier is a persistent body of dense ice that is constantly moving under its own weight, formed where the accumulation of snow exceeds its ablation over many years.
2. What is the intermediate stage in the transformation of snow to glacial ice called?
Correct Answer: b) Névé or Firn
Explanation:
Firn (or névé) is granular snow, especially on the upper part of a glacier, that has not yet been compressed into solid ice but has survived a season of melting.
3. Approximately what percentage of the Earth's land surface is currently covered by glaciers and ice sheets?
Correct Answer: b) 10%
Explanation:
Today, glaciers and ice sheets cover about 10% of the Earth's land area, primarily in Antarctica and Greenland.
4. A continuous mass of ice that covers a large landmass, exceeding 50,000 square kilometers, is known as a(n):
Correct Answer: c) Ice sheet
Explanation:
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 square kilometers. Only two exist today: the Antarctic and Greenland ice sheets.
5. Which type of glacier forms when one or more valley glaciers spread out at the base of a mountain range?
Correct Answer: b) Piedmont glacier
Explanation:
Piedmont glaciers form when steep valley glaciers spill into relatively flat plains, spreading out into bulb-like lobes.
6. Glaciers that terminate in the ocean, actively discharging icebergs, are called:
Correct Answer: a) Tidewater glaciers
Explanation:
Tidewater glaciers are valley glaciers that flow far enough to reach the ocean, where they calve icebergs into the sea.
7. The boundary on a glacier separating the accumulation zone from the ablation zone is called the:
Correct Answer: b) Equilibrium line
Explanation:
The equilibrium line (or snowline) marks the area where annual accumulation of snow perfectly balances the annual ablation (melting and sublimation).
8. If a glacier's accumulation exceeds its ablation, what will happen to the glacier?
Correct Answer: c) It will advance
Explanation:
A positive mass balance (accumulation > ablation) causes the glacier to grow, pushing its terminus further down-valley (advancing).
9. The process by which solid ice changes directly into water vapor without melting is known as:
Correct Answer: b) Sublimation
Explanation:
Sublimation is a component of ablation where ice turns directly into vapor, commonly occurring in cold, dry, high-altitude environments.
10. What is the primary mechanism of internal movement within a glacier below a depth of about 50 meters?
Correct Answer: b) Plastic deformation
Explanation:
Below roughly 50 meters, the pressure from overlying ice is immense, causing the ice to behave plastically and flow rather than break.
11. Glacier movement facilitated by a thin layer of meltwater at the bottom of the glacier is known as:
Correct Answer: b) Basal sliding
Explanation:
Basal sliding occurs when meltwater acts as a lubricant between the glacier's base and the underlying bedrock, allowing the ice mass to slide.
12. The uppermost 50 meters of a glacier, which is characterized by brittle failure rather than plastic flow, is known as the:
Correct Answer: c) Zone of fracture
Explanation:
Because there is less pressure near the surface, the top 50 meters of ice behaves like a brittle solid, fracturing under stress to form crevasses.
13. A deep crack or fracture in the brittle upper section of a glacier is called a:
Correct Answer: c) Crevasse
Explanation:
Crevasses are deep fissures that form in the zone of fracture due to tensional stress as the glacier moves over uneven terrain.
14. A specific type of crevasse that forms at the head of a glacier, separating moving ice from the stationary ice or rock wall above, is a:
Correct Answer: b) Bergschrund
Explanation:
A bergschrund is a large, often deep crevasse that forms where the active, moving glacier ice pulls away from the stagnant ice attached to the mountain.
15. What is a glacier 'surge'?
Correct Answer: b) A short-lived event where a glacier advances at velocities up to 100 times normal
Explanation:
Surge-type glaciers experience periodic phases of extremely rapid flow, often triggered by changes in subglacial hydrology and water pressure.
16. Alternating bands of light and dark ice on a glacier's surface, often formed below icefalls, are known as:
Correct Answer: b) Ogives
Explanation:
Ogives are wave-like bands on the glacier surface that typically form at the base of icefalls, representing seasonal differences in flow and accumulation.
17. The process by which a glacier lifts and removes blocks of fractured rock from its bed is called:
Correct Answer: b) Plucking (quarrying)
Explanation:
Plucking occurs when meltwater enters cracks in the bedrock, freezes, and attaches the rock to the glacier. As the glacier moves, it plucks the rock away.
18. The sandpaper-like erosion caused by rocks embedded in the bottom of a glacier sliding over bedrock is known as:
Correct Answer: b) Abrasion
Explanation:
Abrasion is the scouring and grinding of bedrock by rocks and debris carried in the basal layers of the moving glacier.
19. Linear scratches or gouges in bedrock caused by glacial abrasion are called:
Correct Answer: c) Glacial striations
Explanation:
Glacial striations are parallel scratches carved into bedrock by rocks dragged along the base of the glacier, indicating the direction of ice flow.
20. Fine, pulverized rock dust produced by glacial abrasion is known as:
Correct Answer: b) Rock flour
Explanation:
Rock flour is the extremely fine-grained, silt-sized powder created by the grinding action of glacial abrasion. It often gives glacial lakes a milky turquoise color.
21. Crescent-shaped depressions chipped out of bedrock by the pressure of boulders carried beneath a glacier are called:
Correct Answer: b) Chatter marks
Explanation:
Chatter marks (or crescentic gouges) are series of semi-circular or crescent-shaped fractures chipped out of bedrock by irregular rolling or dragging of subglacial boulders.
22. What shape do alpine glaciers typically give to the valleys they erode?
Correct Answer: b) U-shaped
Explanation:
While rivers carve V-shaped valleys, glaciers erode both the bottom and sides of the valley, creating steep-walled, flat-bottomed U-shaped valleys (glacial troughs).
23. A tributary glacial valley whose floor is situated high above the main U-shaped valley floor is called a:
Correct Answer: b) Hanging valley
Explanation:
Main glaciers erode deeper than smaller tributary glaciers. When the ice melts, the tributary valleys are left 'hanging' above the main valley, often forming waterfalls.
24. A chain of small lakes connected by a stream in a glaciated valley is known as:
Correct Answer: c) Paternoster lakes
Explanation:
Paternoster lakes are a series of step-like glacial lakes in a U-shaped valley, resembling the beads of a rosary.
25. A deeply excavated glacial trough that has been submerged by rising sea levels forms a:
Correct Answer: c) Fjord
Explanation:
Fjords are steep-sided, narrow inlets of the sea formed when coastal glacial U-shaped valleys are flooded after the ice melts and sea levels rise.
26. A bowl-shaped amphitheater-like depression carved into a mountain at the head of an alpine glacier is a:
Correct Answer: c) Cirque
Explanation:
A cirque is an erosional basin formed at the origin of a glacier by plucking and frost wedging against the mountain wall.
27. A mountain lake that forms within an empty cirque basin after a glacier melts is called a:
Correct Answer: a) Tarn
Explanation:
A tarn is a small, deep lake that occupies an ice-gouged cirque basin.
28. A sharp, jagged, knife-edge ridge separating two adjacent glaciated valleys is an:
Correct Answer: a) Arête
Explanation:
An arête is a thin ridge of rock left behind when two parallel glaciers erode their valleys, narrowing the divide between them.
29. A sharp, pyramid-like peak formed when three or more cirques erode a mountain from different sides is a:
Correct Answer: c) Horn
Explanation:
A horn is a pyramidal peak created by headward erosion of multiple cirques surrounding a single high mountain peak. The Matterhorn is a famous example.
30. A low point or saddle in an arête, formed when two opposing cirques erode completely through the ridge, is called a:
Correct Answer: b) Col
Explanation:
A col is a saddle-like mountain pass created by the intersection of two cirques backing into each other.
31. An asymmetrical bedrock hill with a gently sloping, abraded stoss side and a steep, plucked lee side is a:
Correct Answer: b) Roche moutonnée
Explanation:
A roche moutonnée is an erosional bedrock feature. The glacier smooths the side it hits first (stoss) and plucks chunks from the trailing side (lee).
32. A landform featuring a resistant bedrock knob (crag) that protects a tapering trail of softer sedimentary rock or till behind it is called a:
Correct Answer: b) Crag and tail
Explanation:
A crag and tail forms when a highly resistant rock (crag) shelters softer material (tail) on its leeward side from glacial erosion.
33. An isolated mountain peak that protrudes above the surface of a surrounding ice sheet or glacier is a:
Correct Answer: a) Nunatak
Explanation:
Nunataks are exposed, rocky ridges or peaks not covered with ice or snow within an ice field or glacier.
34. The distinct line on the side of a glacial valley marking the maximum historical height of the glacier is the:
Correct Answer: c) Trimline
Explanation:
A trimline is a clear boundary on a valley wall representing the highest extent of recent glacial ice, often separating mature vegetation above from scoured rock or younger vegetation below.
35. What is the general term for all rock material transported and deposited by a glacier or its meltwater?
Correct Answer: b) Glacial drift
Explanation:
Glacial drift is the comprehensive term for all sediments of glacial origin, which is further subdivided into till and stratified drift.
36. Unsorted, unstratified mixture of clay, sand, gravel, and boulders deposited directly by glacial ice is called:
Correct Answer: c) Till
Explanation:
Till is the direct deposit of glacial ice. Because ice cannot sort sediment by size the way water does, till is characteristically an unsorted jumble of rock sizes.
37. Sediment that is deposited and sorted by glacial meltwater streams is known as:
Correct Answer: c) Stratified drift
Explanation:
Stratified drift refers to glacial sediments deposited by meltwater. Because flowing water sorts particles by size, these deposits are layered (stratified).
38. A large boulder transported by a glacier and deposited in an area of completely different bedrock is a:
Correct Answer: b) Glacial erratic
Explanation:
Glacial erratics are rocks carried far from their source by glacial ice. They stand out because their lithology does not match the local bedrock.
39. An isolated rock fragment found within fine-grained marine or lake sediments, typically released from a melting iceberg, is a:
Correct Answer: b) Dropstone
Explanation:
Dropstones are deposited when icebergs carrying glacial debris melt in open water, dropping large stones into the fine muddy sediments of the lake or ocean floor.
40. A ridge of till that marks the furthest advance of a glacier is called a:
Correct Answer: c) Terminal (end) moraine
Explanation:
A terminal moraine is a specific type of end moraine that marks the absolute maximum limit of a glacier's advance.
41. A ridge of till running along the edges of an alpine glacier valley is a:
Correct Answer: d) Lateral moraine
Explanation:
Lateral moraines form along the sides of a glacier, consisting of debris scraped from the valley walls and material falling onto the ice.
42. When two valley glaciers merge, their inner lateral moraines join to form a dark stripe of debris down the center of the new glacier called a:
Correct Answer: a) Medial moraine
Explanation:
A medial moraine is formed when two glaciers meet, and their adjacent lateral moraines combine to form a central ridge of debris carried down-glacier.
43. A ridge of till deposited behind the terminal moraine during temporary halts in a glacier's retreat is a:
Correct Answer: b) Recessional moraine
Explanation:
Recessional moraines are created during pauses in a glacier's retreat, acting as 'pause marks' that show where the terminus temporarily stabilized.
44. A rolling, irregular blanket of till deposited evenly as a glacier rapidly retreats is called a:
Correct Answer: a) Ground moraine
Explanation:
Ground moraine forms a gently undulating surface of till deposited steadily as the glacier base melts and retreats.
45. An elongated, teardrop-shaped hill of glacial till streamlined by overriding ice is a:
Correct Answer: b) Drumlin
Explanation:
Drumlins are asymmetrical hills of till. The steep side faces the direction from which the ice advanced, and the gentle, tapering side points in the direction of ice flow.
46. Unlike a roche moutonnée, the steep side of a drumlin faces:
Correct Answer: a) Up-glacier (the direction the ice came from)
Explanation:
In a drumlin, the steep (stoss) side faces up-glacier. In an erosional roche moutonnée, the steep, plucked (lee) side faces down-glacier.
47. A long, winding ridge of stratified sand and gravel deposited by a subglacial meltwater stream is an:
Correct Answer: b) Esker
Explanation:
Eskers are the cast remnants of streams that flowed in tunnels under or within the melting glacier, leaving sinuous ridges of sorted sediment.
48. An irregular mound or hill of stratified drift deposited in depressions on the surface of a melting glacier is a:
Correct Answer: a) Kame
Explanation:
Kames are mounds of sand and gravel formed when meltwater washes sediment into holes or crevasses on stagnant ice. When the ice melts, the sediment slumps into a mound.
49. A flat-topped ridge of stratified drift deposited between a melting glacier and the adjacent valley wall is a:
Correct Answer: b) Kame terrace
Explanation:
Kame terraces form when streams deposit sediment along the margin of a valley glacier and the rock wall. Once the ice melts, the terrace is left suspended on the valley side.
50. A depression or lake formed when a block of stagnant ice is buried in drift and subsequently melts is a:
Correct Answer: b) Kettle
Explanation:
Kettles (or kettle lakes) are steep-sided holes left behind in an outwash plain or moraine after a buried block of glacial ice melts.
51. A broad, flat area of stratified drift deposited by meltwater streams beyond the terminal moraine of an ice sheet is an:
Correct Answer: a) Outwash plain
Explanation:
An outwash plain (or sandur) is a wide expanse of sand and gravel deposited by braided meltwater streams flowing away from the terminus of a glacier.
52. A massive, sudden outburst flood caused by the failure of an ice dam or subglacial geothermal melting is called a:
Correct Answer: b) Jökulhlaup
Explanation:
Jökulhlaup is an Icelandic term for a massive glacial outburst flood, which can dramatically alter landscapes in a very short time.
53. Meltwater streams flowing across an outwash plain typically exhibit which channel pattern due to high, fluctuating sediment loads?
Correct Answer: c) Braided
Explanation:
Glacial outwash streams are usually braided because they are choked with coarse sediment and experience highly variable daily and seasonal discharges.
54. Vast, unstratified deposits of windblown silt, largely derived from fine glacial outwash material during the Pleistocene, are called:
Correct Answer: b) Loess
Explanation:
Much of the world's loess (such as in the US Midwest) originated as rock flour from glacial outwash plains, which was then picked up and deposited by strong winds.
55. A lake formed immediately in front of a retreating glacier, typically trapped between the ice margin and a moraine, is a:
Correct Answer: a) Proglacial lake
Explanation:
Proglacial lakes form just ahead of the glacier margin, often dammed by the ice itself or by terminal moraines.
56. What was the name of the massive Pleistocene proglacial lake in North America that covered parts of Manitoba, Ontario, and North Dakota?
Correct Answer: c) Lake Agassiz
Explanation:
Lake Agassiz was an immense proglacial lake formed by meltwater from the retreating Laurentide Ice Sheet.
57. Lakes that formed in currently arid regions during the Pleistocene due to cooler temperatures and higher precipitation (lower evaporation) are called:
Correct Answer: b) Pluvial lakes
Explanation:
Pluvial lakes, such as Lake Bonneville (ancestor of the Great Salt Lake), formed far from the ice sheets in the Great Basin due to a cooler, wetter Ice Age climate.
58. Pairs of alternating light (summer) and dark (winter) sediment layers deposited annually in glacial lakes are called:
Correct Answer: a) Varves
Explanation:
Varves are rhythmic, alternating layers of silt/sand (summer melt) and clay (winter freeze), allowing geologists to count years of glacial history.
59. The extremely slow upward movement of the Earth's crust following the melting of massive ice sheets is known as:
Correct Answer: a) Isostatic rebound
Explanation:
Glacial isostatic adjustment (or rebound) occurs because the immense weight of ice sheets depresses the crust into the mantle. When the ice melts, the crust slowly rises back up.
60. The most recent geological epoch, characterized by multiple extensive glaciations (Ice Ages), is the:
Correct Answer: b) Pleistocene Epoch
Explanation:
The Pleistocene Epoch spanned from about 2.58 million to 11,700 years ago and is famous for its repeated cycles of glacial advances and retreats.
61. Which massive ice sheet covered most of Canada and the northern United States during the Last Glacial Maximum?
Correct Answer: c) Laurentide Ice Sheet
Explanation:
The Laurentide Ice Sheet was the primary ice mass over eastern and central North America, profoundly shaping the landscape, including the Great Lakes.
62. Which ice sheet covered much of northern Europe, including Scandinavia and parts of the UK, during the Pleistocene?
Correct Answer: b) Fennoscandian Ice Sheet
Explanation:
The Fennoscandian Ice Sheet was the massive ice body centered over Scandinavia that scoured northern Europe during the Pleistocene glaciations.
63. The cyclical variations in Earth's orbit that pace the onset and end of ice ages are known as:
Correct Answer: b) Milankovitch cycles
Explanation:
Milutin Milankovitch identified three cyclical variations in Earth's orbit—eccentricity, obliquity, and precession—that influence solar radiation distribution and trigger glacial cycles.
64. Which component of the Milankovitch cycles refers to the variation in the tilt of the Earth's axis (between 22.1 and 24.5 degrees)?
Correct Answer: c) Obliquity
Explanation:
Obliquity is the tilt of Earth's axis. A smaller tilt results in cooler summers at high latitudes, which prevents winter snow from melting and allows glaciers to grow.
65. Which component of the Milankovitch cycles refers to the changing shape of Earth's orbit from circular to elliptical over a 100,000-year cycle?
Correct Answer: c) Eccentricity
Explanation:
Eccentricity describes the elliptical nature of Earth's orbit, which dictates the severity of seasonal variations based on Earth's distance from the Sun.
66. Which component of the Milankovitch cycles describes the 'wobble' of Earth's axis over a 26,000-year cycle?
Correct Answer: b) Precession
Explanation:
Axial precession is the wobble of Earth's axis, like a spinning top, changing which hemisphere is pointed at the sun during perihelion and aphelion.
67. As ice sheets expand, they reflect more solar energy back to space, causing further cooling. This is an example of:
Correct Answer: b) Ice-albedo positive feedback
Explanation:
White ice has a high albedo (reflectivity). As ice expands, more sunlight is reflected rather than absorbed, cooling the planet further and causing more ice to form (a positive feedback loop).
68. In glacial ice cores, a higher ratio of the heavy oxygen isotope (O-18) compared to the lighter isotope (O-16) indicates:
Correct Answer: b) A period of warmer global climate
Explanation:
In ice cores, warmer temperatures provide the energy needed to evaporate the heavier O-18 from the oceans, resulting in higher O-18 levels in the snow that falls on ice sheets during warm periods.
69. Environments adjacent to glaciers, or non-glaciated regions dominated by frost action and cold climates, are called:
Correct Answer: b) Periglacial
Explanation:
Periglacial environments are characterized by intense freezing and thawing cycles and permafrost, but they are not permanently covered by glacial ice.
70. Soil, rock, or sediment that remains below freezing (0°C) for two or more consecutive years is known as:
Correct Answer: b) Permafrost
Explanation:
Permafrost is a defining feature of periglacial zones, referring specifically to the thermal condition of the ground remaining below freezing for at least two years.
71. The top layer of soil above permafrost that thaws in the summer and freezes in the winter is the:
Correct Answer: b) Active layer
Explanation:
The active layer is the highly dynamic, shallow surface layer of soil in a permafrost region that undergoes annual freezing and thawing.
72. An unfrozen patch of ground within a permafrost region, often found beneath lakes or rivers, is called a:
Correct Answer: b) Talik
Explanation:
A talik is a localized area of unfrozen ground in a continuous permafrost area, typically kept liquid by the thermal mass of an overlying water body.
73. A massive, ice-cored mound or hill found in permafrost regions is known as a:
Correct Answer: a) Pingo
Explanation:
Pingos are earth-covered mounds with a solid core of ice. They grow as pressurized groundwater freezes and expands beneath the surface.
74. The repeated freezing and thawing of soil in periglacial areas often sorts coarse stones from fine soil, creating geometric shapes on the surface called:
Correct Answer: b) Patterned ground
Explanation:
Patterned ground consists of polygons, circles, or stripes of sorted stones formed by frost heaving in periglacial environments.
75. The slow, downslope flow of water-saturated soil over an impermeable layer of permafrost is called:
Correct Answer: b) Gelifluction (Solifluction)
Explanation:
When the active layer thaws in summer, the water cannot penetrate the permafrost below. The waterlogged soil flows slowly downslope in a process called gelifluction (a specific type of solifluction).
76. Irregular, hummocky terrain created by the thawing of ice-rich permafrost, leading to ground collapse and small lakes, is called:
Correct Answer: b) Thermokarst
Explanation:
Thermokarst resembles limestone karst but is formed purely by the thermal melting of ground ice, causing the surface to slump into depressions.
77. A tongue-shaped mass of angular rock debris bound by interstitial ice, flowing slowly down a mountain valley, is a:
Correct Answer: a) Rock glacier
Explanation:
Rock glaciers look like glaciers but are composed primarily of rock fragments held together by ice, flowing very slowly via the deformation of that ice.
78. What is the term for the vertical shaft in a glacier through which surface meltwater flows down to the base?
Correct Answer: b) Moulin (glacier mill)
Explanation:
A moulin is a roughly circular, vertical to nearly vertical well-like shaft within a glacier through which meltwater enters from the surface.
79. Dust, soot, and microbes that collect in small, water-filled holes on a glacier's surface and accelerate localized melting are called:
Correct Answer: b) Cryoconite
Explanation:
Cryoconite is dark, powdery windblown dust (rock, soot, microbes) that absorbs solar radiation and melts small cylindrical holes into the ice surface.
80. Transport of sediment occurring completely within the body of the glacier ice is called:
Correct Answer: c) Englacial transport
Explanation:
Englacial transport refers to debris carried within the ice, which often entered through crevasses or was buried by subsequent snowfall.
81. Debris carried on the very surface of a glacier is undergoing:
Correct Answer: c) Supraglacial transport
Explanation:
Supraglacial transport refers to material riding on top of the glacier, usually derived from rockfalls off adjacent valley walls.
82. Till deposited under immense pressure directly beneath a moving glacier is termed:
Correct Answer: b) Lodgement till
Explanation:
Lodgement till is 'plastered' or smeared onto the underlying bedrock beneath actively advancing ice, resulting in highly compacted, dense sediment.
83. During the Last Glacial Maximum (LGM) around 20,000 years ago, global sea levels were approximately:
Correct Answer: c) 120 meters lower than today
Explanation:
Because millions of cubic kilometers of ocean water were locked up in massive continental ice sheets, global sea levels dropped by about 120-130 meters.
84. The 'Snowball Earth' hypothesis proposes that:
Correct Answer: b) During the Neoproterozoic Era, the Earth's surface became entirely or nearly entirely frozen
Explanation:
The Snowball Earth hypothesis suggests that around 600-700 million years ago, runaway ice-albedo feedback caused glaciation to reach the equator.
85. Currently, almost all of the world's mountain glaciers are:
Correct Answer: c) Experiencing net mass loss and retreating
Explanation:
Due to anthropogenic climate change and global warming, the vast majority of alpine glaciers worldwide have negative mass balances and are retreating.
86. Which specific isotopic proxy is most frequently analyzed in the calcium carbonate shells of foraminifera to determine ancient glacial ice volumes?
Correct Answer: b) Oxygen-18 (18O)
Explanation:
During glaciations, lighter Oxygen-16 is locked in ice sheets, leaving the oceans enriched in heavier Oxygen-18, which is then recorded in marine fossils.
87. A rock that has been lithified from ancient glacial till is known as:
Correct Answer: b) Tillite
Explanation:
Tillite is the sedimentary rock formed when glacial till becomes lithified (turned to stone) over geologic time, providing evidence of ancient glaciations.
88. What happens to the snowline/equilibrium line altitude (ELA) during a period of global warming?
Correct Answer: c) It shifts to a higher altitude
Explanation:
As temperatures rise, the zone where melting occurs expands upward, forcing the equilibrium line to a higher altitude.
89. Which of the following defines 'ablation' in glaciology?
Correct Answer: b) The overall loss of ice and snow from a glacier
Explanation:
Ablation refers to all processes that remove mass from a glacier, including melting, sublimation, calving, and wind erosion.
90. What is 'calving'?
Correct Answer: b) The breaking off of chunks of ice at the edge of a glacier, forming icebergs
Explanation:
Calving is the mechanical failure of ice at the terminus of a tidewater glacier or ice shelf, resulting in icebergs falling into the water.
91. Which ice sheet is currently the largest on Earth?
Correct Answer: c) Antarctic Ice Sheet
Explanation:
The Antarctic Ice Sheet is the largest single mass of ice on Earth, containing about 60% of all fresh water on the planet.
92. An accumulation of debris that was dropped passively from melting ice without being subjected to significant pressure is termed:
Correct Answer: b) Melt-out till
Explanation:
Melt-out till forms when stagnant or slow-moving ice melts, allowing the englacial and supraglacial debris to gently drop and accumulate on the ground.
93. If all the ice on Antarctica and Greenland were to melt completely, global sea levels would rise by approximately:
Correct Answer: c) 65 meters
Explanation:
Current estimates suggest that the total melting of the Antarctic and Greenland ice sheets would raise global sea levels by about 65 to 70 meters.
